I am doing my first model that actually needs painted supports and not having much luck, wondering what I’m doing wrong and if this is something I might need to adjust in CAD rather than slicer.
I need to support the “legs” of this part about half way up since when I don’t, they get all wobby when printing and either fail completely or are way off center when they finally all connect on top.
First I tried to just set the support threshold to 89* and then 90*, it highlights the legs as it should, but it never generates any supports for them.
So, I manually painted some lines about half way up the legs, and it does generate supports exactly how I want, but, it doesn’t actually connect them to the legs. I tried adjusting top and bottom Z height, but that didn’t work, I figured maybe because they are trying to connect to an almost vertical wall, so I tried adjust the xy distance to 0, which I learned causes the slicer to crash with a “can’t divide by zero” error, so I tried setting it to 0.01 which lets it slice, but the supports still aren’t connecting to the legs.
They do sort of support them during printing by just wrapping around them as shown in the preview, but the legs still wobble when being printed on and still end up moving too much before the top connecting bridges are layed down.
Is there something I’m doing wrong or a way I can get them to actually connect to the legs? I figure I can add some little blocks to the legs in the design itself so give the supports a horizontal surface to connect to, but then I’d have to cut them off after, and the legs are already brittle (ASA), so I’d like to avoid that.
But that being said, those legs should absolutely not require supports. Really, anything with a slope angle greater than 45º should not require supports. These look like they’re closer to 75º or maybe higher…
As I said in OP that was the first thing I tried, setting it to 89* and even 90*, it never generated support for them. The legs need support because they wobble when the higher layers are being printed onto them and eventually break off or bend and by the time the top part that links them all together goes on, they are way off from where they should be.
Set a higher minimum layer time for those areas. Slow the printhead down, they’ll wobble less.
You may not be able to generate supports there. The surfaces are too vertical. The slicer wants an interface layer and that steep angle probably prohibits it…
I’m already super slow for better layer adhesion with ASA…I was hoping the new “allow support on vertical surfaces” feature on 1.10 would help since that’s exactly what I need, but it doesn’t
You really do not want the supports to connect and leave a scar, you just want to stop the wobbles. Just use the smallest support/object xy distance value that does not crash the slicer. Instead of painting supports halfway up, try painting them at 1/3 and 2/3 up.
The Studio version released today (1.10.00.89) greatly improves supports on vertical surfaces. I set the x-y distance to 0.001 mm and it still managed to slice this skinny 2x200 mm cylinder without crashing. It did have to think about it for a while.
I tried 0 for xy but it crashes, so I have it set to 0.01. There is still a noticeable gap between the supports and legs. I am going to try Ikarus suggestion of just using more of them at various places hoping they all wrap around them enough to fully support them during printing.
I do agree with @RocketSled that this should not really require supports. Although I do not have experience with ASA, I have seen similar issues using PETG and PLA on geometries with thin, truss-like parts printed vertically. The main problem with those is the lack of heat dissipation before the next layer is added. This causes curling, then wobbling and print failure not long after.
Unfortunately, the slicer logic behind minimum layer time just slows down the nozzle. That leads to the hot nozzle being in longer contact to the part, injecting even more heat.
Instead, you could (in addition to setting a very low layer height in the truss region through adaptive layer lines as suggested by @RocketSled ) try either enforcing a prime tower using “Timelapse” → “Smooth” and/or print two or three parts on the same plate.
This is a delicate balance for sure, I am using polymaker ASA, which I have found, in my experience at least, loses layer adhesion very quickly if you let it cool down too much. I actually use a heated chamber when printing it, so I presume that I am fighting an uphill battle keeping the heat up, while needing the legs to stay cool and stiff.
Well, you do have a number of options, but it will probably take some experimentation.
Supports do not only work for stabilization (although the increasing lever arm to the build plate makes them less effective the higher the model), they also increase layer time slightly which is helpful if the nozzle is kept away from the part.
Adaptive layer height allows you to locally tailor the heat input (and hence needed cooling) per nozzle pass. It is quite powerful in this respect as it is a cubic relationship. Halving the local layer height decreases the heat input (and hence needed cooling) by a factor of 8.
And finally, the prime tower and/or part multiplication. Check the maximum layer time of your print out of heat bed effect (i.e. around 2cm up). You definitively have that much time for the higher layers. However, you only need a minor total increase in layer time (which may however be a significant relative increase) higher up.
I tried a mix of different things, I had been avoiding using the standard (non tree) supports since it added a lot of time, I tried tree hybrid and also standard and standard seems to support the legs the best, using 0.01 xy distance. A few little scars were on the legs where the support wrapped around it but easily came off with a fingernail.
The end result is good enough for the purpose.
Now to figure out how to get my polymaker ASA layer adhesion closer to PLA levels. I prototype everything in Sunlu recycled (garbage) PLA that prints at 190C and even the prototypes were much harder to break (at the legs) than these ASA parts, the layer adhesion just isn’t ther for some reason.
